Process of manufacturing chlorates by electrolysis.



No. 633,272. Patented Sept. l9, I899.

T. PARKER. I

PROCESS OF MANUFACTURING CHLOBATES BY ELECTBOLYSIS.

(Apylics-tion filed Dec. 22, 1897.)

ikmyv w greatly increased efficiency compared with the of one or moremetal plates 0 between two UNITE STATES PATENT OFFICE.

THOMAS PARKER, or TETTENHALL, ENGLAND.

PROCESS OF MANUFACTURING CHLORATES BY ELECTROLYSIS.

srncrrmarmn forming pea of Letters Patent No. 633,272, dated September19, 1899.

Application at DecemberZZ, 1897- To all whom it may concern:

Be it known that I, THOMAS PARKER, a subject of the Queen of GreatBritain, residing at Tettenhall, near Wolverhampton, in the county ofStafford, England, have invented certain new and useful Improvements inthe Electrolytic Production of the Ohlorates of Sodium and Potassium, ofwhich the following is a specification.

This invention relates to electrolytic production of the chlorat'es ofsodium and potassium; and it has for its object to insure a meansordinarily employed in the production of such chlorates.

The invention consists in the method of procedure employed in theelectrolytic operation, and the construction of the cell employed isillustrated in the accompanying drawings, wherein- Figure 1 is alongitudinal section, Fig. 2 a plan, and Fig. 3 a transverse section, ofa double cell constructed and constituted according to this invention. I

The tank A, which is the cathode, is mad of sheet or thin plate metal,conveniently iron. The top edge of the tank is surrounded by anangle-metal stiffener a, which serves also to support longitudinalbearers b,of wood. These bearers I) support cross-bearers 0, upon whichrest longitudinal copper rods d, to which the pieces of carbon B formingthe anode are connected by means of hook-bolts e. The hinder ends ofthese boltsare hooked over the bars at and their forward ends are passedthrough the respective pieces of carbon and have wing-nuts f screwedthereon to tighten the carbons against the bars 01. Any carbon B maythus be readily removed and replaced without interfering with theworking of the cell. The tank itself forms, as above stated, thecathode, and the surface area of the oathode may be increased by theintroduction adjacent rows of the carbons indicated in-the drawings. Asshownin the drawings, the cell becomes a double one. If two or moremetal I plates, such as C, be placed within the tank, each by itselfbetween two adjacent rows .of carbons, the'cell becomes triple,quadruple, 850., "according to the number of plates used. The plate orplates 0 are provided with holes Serial No. 663,069. (No specimens.) I

g' therethrough, or theyare otherwise of such character as to allow freecommunication between the solution or liquid on opposite sides thereof,and the plate or plates are of course electrically connected with themetal tank in a manner which constitutes it part of the cathode. If noplate 0 is inserted within the tank, one row only of carbons is used andthe cell is then a simple or single cell. In practice any desired numberof single, double, treble, &c., cells may of course be worked togetherin series.

The solution D, Fig. 3, in the cell is'sodium or potassium chlorid or asolution of these chlorids mixed and is free from alkaline carbonates bypreference. A diaphragm is omitted altogether and the solution iscovered with a thick layer of some buoyant non-conducting substance E,Fig. 3, as pumice-stone, cork, or the like, preferably pumice-stone inbits of about the size of a hazelnut, the layer being about oneinchdeep. The purpose of this pumice or floating material is to scrub theescaping gases, and thereby prevent them from carrying off any portionof the solution forming the electrolyte.

' The surface areas of the anode (at the surface of which the chlorin isliberated) and of the cathode will be of course arranged to insure acurrent density suitable for economical workingthat is to say, abouttwenty amperes per square foot of the superficial area of the cathode.

The carbons B shown in the drawings are bits of gas-carbon; but moldedor prepared carbons may be used as well, or platinum may be used in lieuof. carbon for the anodes.

An important feature of the invention consists in the maintenance of thetemperature of the cell at about 30 to 40centigrade during the Working,and this is most conveniently effected by regulating the currentdensity, as above stated, at about twenty amperes per square foot ofcathode area. The advantage gained by maintaining such low temperaturein the cell is'this: In ordinary working with the usual apparatus thereis a small anode and cathode area, and consequently a relatively highcurrent density at their surfaces, with the result that theelectrolyte'is heated, and thus current is wasted in raising thetemperature of the electrolyte. Thepresent invention provides a largeanode and cathode area, and thus permits a lower current density to beused, and this insures a low temperature in working, no current beingwasted in heating the electrolyte. Obviously the advantage lies inavoiding against loss of current, and the construction of the apparatusemployed permits of effecting this saving. It will be observed also thatin carrying out this invention the anode-surfaces are separated from thecathode-s11 rfaces by the electrolyte only, no porous protectingmaterial being interposed, as in ordinary cases. Where such material isemployed, the apparatus cannot be worked at as low a voltage as where itis not required, and consequently the use of such an intermediate tosome extent impairs the eificiency of the apparatus. This apparatusrequires no protective lining for the cell, as the metal liberated atthe cathodesuriace is in itself a suflicient protection.

Any suitable generator of electricity may be employed in the operation,the anodes and cathodes forming, of course, parts of the circuit.

Having thus described my invention, I claim 1. The herein-describedmethod of carrying on the prod nction by electrolysis of chlorates,

directly from an electrolyte consisting of an aqueous solution of analkali-metal chlorid, which consists in passing a current of electricitythrough said solution while the latter is covered with a layer of somebuoyant nonconducting material, whereby the gases disengaged arescrubbed, and maintaining the current density during the operation, atabout twenty ampe'res per square foot, substantially as set forth.

2. The herein-described method of carrying on the production byelectrolysis of chlorates, directly from an electrolyte consisting of asolution of an alkali-metal chlorid, which consists in passing a currentof electricity through said electrolytefrom the anode to the cathode,separated only by the electrolyte, said solution being covered with alayer of some buoyant non-conducting material whereby the gasesdisengaged are scrubbed, substantially as set forth.

In witness whereof I have hereunto signed my name in the presence of twosubscribing witnesses.

THOMAS PARKER.

\Vitnesses:

STEPHEN \VATKINS, ROBERT M. LESTER.

